The present invention relates to an unmanned aircraft, an unmanned aviation system and a method for avoiding collisions when flying an unmanned aircraft.
Unmanned aircraft are gaining increasing importance in the military arena, and also for civilian applications, in particular for research purposes. In an unmanned aircraft, no pilot is on board to fly the aircraft, as is already indicated by the name. Rather, the flight operation is computer controlled, for example, with the help of a specified route. Moreover, a connection to a control station can be provided, to make it possible to operate the unmanned aircraft by remote control. German Patent Document DE 19849857 C2 describes, for example, a remote control operation method for an unmanned aircraft in which the aircraft can be remotely controlled from the control station on a flight path that is different than a pre-programmed safe route. In the event of the presence of an imminent collision, an obstacle avoidance maneuver can be performed manually in the control station by the respective operator. It has been shown, however, that manually performed obstacle avoidance maneuvers cannot always prevent a collision, for example, because of input errors.
Therefore, there is a need for providing an unmanned aircraft having an improved obstacle avoidance process.
According to an exemplary embodiment of the invention, an unmanned aircraft is provided that has a lift system and a propulsion system and a flight control system. The flight control system has a flight control unit, a navigation system and an actuator system. The flight control unit has an autopilot unit. The flight control unit is provided to calculate control commands by using data from the navigation system and/or the autopilot unit, which can be supplied to the actuator system to activate the lift and propulsion system. Moreover, a collision warning system is provided, which is connected with the flight control system, whereby the collision warning system detects a collision situation and provides obstacle collision avoidance data. A connection between the collision warning system and the autopilot unit is provided in order to initiate an obstacle avoidance maneuver by the autopilot unit with the aid of the collision avoidance data.
According to an exemplary embodiment of the invention, a data connection system is provided to connect with a control station for controlling and monitoring the flight operation of the unmanned aircraft. The data connection system is provided with a prevention mechanism with which the execution of the obstacle avoidance maneuver can be prevented at least temporarily.
For example, the connection between the collision warning system and the autopilot unit can be blocked temporarily. The blocking of the connection between the collision warning system and the autopilot unit can be initiated by the control station. According to a further example of the invention, the collision warning system can be deactivated by the prevention mechanism.
Aborting the obstacle avoidance maneuver can also take place as a result of supplying a specific abort signal to the autopilot, i.e., the data connection remains intact and is not interrupted, but rather, the abort signal is transmitted by the autopilot unit, whereby as a result, it is possible to abort the intended obstacle avoidance maneuver.
Therefore, it can be said for the exemplary embodiment of the unmanned aircraft having the data connection system and the prevention mechanism that it is possible to supply an external signal to the unmanned aircraft, for example, via the data circuit system, whereby it can also be a data circuit system that is already used otherwise, in order to bring about an abort by the autopilot unit, or at least a temporary interruption of the obstacle avoidance maneuver.
In the event an obstacle avoidance maneuver is not initiated at all, feeding a signal into the prevention mechanism causes the autopilot to be activated in such a way and/or adjusted, that when a collision situation is detected, an obstacle avoidance maneuver does not happen. This can be the case, for example, when the collision warning mechanism or the collision warning system does not make a corresponding required signal that represents the obstacle avoidance maneuver available to the autopilot. But it is also possible that the collision warning system conveys the corresponding information of the necessity of an obstacle avoidance maneuver to the autopilot, that there, however, the signal that has been received has no effect at all, i.e., that no obstacle avoidance maneuver is initiated, at least not until a corresponding signal or a corresponding instruction is present, which prevents the execution of an obstacle avoidance maneuver.
In aviation, the responsibility of avoiding a collision can be divided into two ranges, for which reason the term of division into several ranges can be used: An outer range serves the superordinated separation of the aircraft, whereas an inner range is for collision avoidance, i.e., for those cases that cannot be solved by the separation layer. The separation takes place depending on the actual airspace and the flight rules, according to which the aircraft is operated, by the aviation control instance (Air Traffic Control, ATC) or in a manned aircraft, by the pilot. In manned aircraft, the inner layer is always represented by the pilot. For unmanned aircraft according to the invention, a technical solution is provided for the inner collision avoidance layer.
According to an exemplary embodiment of the invention, the collision warning system has at least two modes of operation, whereby the modes of operation can be activated automatically.
According to an exemplary embodiment of the invention, the operating modes can be activated automatically by operating parameters of the aircraft and/or by the flight data.
For example, the execution of an obstacle avoidance maneuver when a specified operating mode is activated can be prevented at least temporarily. According to a further example, in a first mode, in the case of a detected collision situation, collision warnings and obstacle avoidance recommendations can be generated and emitted; in a second mode, in the case of a detected collision situation, only collision warnings can be generated and emitted; in a third mode, in the event of a detected collision situation, no collision warnings or obstacle avoidance recommendation can be emitted.
For example, when the landing gear is deployed, an operating mode can be activated in which obstacle avoidance maneuvers are prevented. For example, when deploying the landing gear, only collision warnings can be generated and emitted. According to a further example of the invention, in the event of a defect in the actuator system and/or the lift system and propulsion system, for example, in the event of a powerplant fault, an operating mode can be activated in which obstacle avoidance maneuvers are prevented, or an operating mode in which only collision warnings are generated and emitted.
According to a further aspect of the invention, the collision avoidance data include instructions for an obstacle avoidance maneuver that related to the ascent rate/descent rate of the aircraft. According to a further aspect of the invention, the collision avoidance data can also include instructions that relate to a change in the flight path of the aircraft. According to a further aspect of the invention, the instructions can pertain to the ascent rate/descent rate as well as the change in flight path of the aircraft.
According to an exemplary embodiment of the invention, when the data connection fails, the collision warning system can be automatically connected with the autopilot unit, and in the case of a detected collision situation and generated collision avoidance data, an obstacle avoidance maneuver can be executed automatically by the autopilot unit.
This ensures improved safety when operating an unmanned aircraft according to the invention, for example, in the case of a break in the data link or in the case of transmission delays.
The objective of the invention is also achieved by an unmanned aviation system, which has at least one unmanned aircraft, at least one control station and a data connection. The aircraft is designed according to one of the exemplary embodiments, aspects or examples cited in the preceding text. The control station is used for controlling and monitoring the flight operation of the unmanned aircraft. The data connection is provided between the control station and the unmanned aircraft. The control station has an input unit with which a signal can be generated that can be fed to the unmanned aircraft by using the data connection, in order to bring about an at least temporary prevention of an obstacle avoidance maneuver.
In the aircraft system according to the invention, one or more unmanned aircraft can be controlled by a control station. But in the aviation system according to the invention, respectively one control station can also be provided for an unmanned aircraft. For the sake of simplicity, the variant having one control station and one unmanned aircraft will be described in the following, which to the extent applicable, also applies, however, to the other possible combinations.
For example, via the control station, the obstacle avoidance maneuver controlled by the autopilot unit can be influenced using the data connection, for example, for controlling or regulating or also aborting.
According to an exemplary embodiment of the invention, the control station has a man/machine interface, which is provided with a display, whereby the collision avoidance data can be shown on the display.
According to an exemplary embodiment of the invention, the collision avoidance data have control commands for the obstacle avoidance maneuver, which can be represented as text.
The control commands can be instructions about the rate of ascent/descent and/or a change in flight path. Allowed ranges pertaining to the control command can be displayed. The collision avoidance data can have various directive steps and/or warning steps, whereby the directive steps and/or warning steps can be displayed by a graphic representation of the control commands. For example, the respectively activated mode of operation can be displayed.
The objective of the invention is also achieved by a method for collision avoidance during the flight operation of an unmanned aircraft, which includes the following steps:
a) Detecting a collision situation with a collision warning system of the unmanned aircraft;
b) generating collision avoidance data by the collision warning system;
c) supplying the collision avoidance data to an autopilot unit of the unmanned aircraft, and
d) initiating an obstacle avoidance maneuver by the autopilot unit.
According to an exemplary embodiment of the invention, a prevention signal is conveyed to a prevention mechanism, and at least one obstacle avoidance maneuver is at least temporarily prevented.
For example, the prevention signal causes the connection of the collision warning system to the autopilot unit to be temporarily interrupted or blocked.
The interruption of the execution of an obstacle avoidance maneuver can be performed in various ways. For example, in the case of a signal received via the data connection system for the activation of the prevention mechanism, the obstacle avoidance maneuver can be terminated immediately, and a flight direction can be activated, which causes a successive return to the original flight path or to a specified flight route. According to another example, the return to the originally provided flight path can also take place in as short a period of time as possible, whereby the period of time depends on the possible flight maneuvers in which a stall can be avoided with sufficient certainty. According to a further example, the return to the original flight path can also take place at a significantly later point in time, in order to prolong the duration of the flight as little as possible. The initiation of an abort of an obstacle avoidance maneuver can, as has already been indicated, be subject to an interruption of the data connection, whereby this can be caused by an interruption of the data stream in a physically maintained data connection, or also by an actual physical break of the data circuit, for example by a break in a cable connection.
For example, the prevention signal causes that the unmanned aircraft is returned to the specified corridor and/or the goal. For example, the unmanned aircraft can be returned to the originally planned trajectory.
According to an exemplary embodiment of the invention, the prevention signal is generated by a control station for controlling and monitoring the flight operation of the unmanned aircraft and is conveyed to the unmanned aircraft by a data connection.
According to an exemplary embodiment of the invention, when the data connection fails, the collision warning system will automatically be connected with the autopilot unit, and in the event a collision situation has been detected and collision avoidance data have been generated, the autopilot unit automatically performs an obstacle avoidance maneuver.
According to a further aspect of the invention, switching to the autopilot in the case of an interrupted connection ensures that the on board collision warning system performs a safety net function not representing a routine tool relative to the flight operation of the unmanned aircraft. Although to ensure the necessary distance between aircraft, the flight can be influenced in advance by a control station, however, potential latencies in the data link, i.e., the connection, represent a problem. When the data link is interrupted, it is ensured according to the invention, that the obstacle avoidance maneuver will be performed, as it takes place independent of the manual intervention of an operator. The automatic obstacle avoidance is also advantageous because the time budget available for initiating the obstacle avoidance maneuver is very limited, which also means that unnecessary obstacle avoidance maneuvers are not desirable.
For example, the unmanned aircraft has a flight control system having a flight control unit, an actuator system and a navigation system. Furthermore, an air data system can be provided. The flight control unit further includes the autopilot unit. The flight control unit calculates control commands—using data from the navigation system and the autopilot unit and if necessary, data from the air data system—which are fed to the actuator system for activating the lift and propulsion system to fly the unmanned aircraft.
For example, the autopilot unit can—upon the conclusion of an obstacle avoidance maneuver and also if necessary, upon an interrupted obstacle avoidance maneuver, guide the unmanned aircraft back to the specified flight path, i.e. corridor or trajectory and/or to the goal.
It should be noted that the characteristics of the exemplary embodiments, forms of embodiments and aspects of the mechanisms also apply to embodiment forms and aspects and/or examples of the method and vice versa.
Furthermore, those characteristics for which this is not explicitly cited can be freely combined with each other.